If I swap out the original "retarded" timing chain and gearset for an upgraded Cloyes version that has '68-'71 timing, will I need a different cover? Is there any interference with the block? Is it just a straight swap?

Thanks, in advance (no pun intended ) for any answers!

 

I believe the answer is no. I just changed a factory timing set for a Cloyes double roller set in an '86 motor with a D-9 block, and a rear sump placed dipstick. The physical dimensions of the original and replacement gears and chains were nearly identical.
I also compared the same Cloyes with a factory gear and chain from a 460 out of a '77 F-250. This engine has a D-1 casting, but has the dipstick in the front cover (instead of in the rear sump). The physical dimensions of the gears and chains were not appreciably different.
Based upon these observations of two series of the same engine, I would believe that the gears should make no difference on the timing over used.

 

I believe the answer is no. I just changed a factory timing set for a Cloyes double roller set in an '86 motor with a D-9 block, and a rear sump placed dipstick. The physical dimensions of the original and replacement gears and chains were nearly identical.
I also compared the same Cloyes with a factory gear and chain from a 460 out of a '77 F-250. This engine has a D-1 casting, but has the dipstick in the front cover (instead of in the rear sump). The physical dimensions of the gears and chains were not appreciably different.
Based upon these observations of two series of the same engine, I would believe that the gears should make no difference on the timing over used.

 

Thanks for your quick response! I, too, have a rear sump dipstick (my engine's an '83 as you know), so it should work for me, as well.

Thanks again!